function prim(a)
 if(a<=1)return false
 if(a<=3)return true
 if(a%2==0 or a%3==0)return false
 for i=5,sqrt(a)\1+1,6 do
  if(a%i==0 or a%(i+2)==0)return false
 end
 return true
end

function spiral(✽)
	local x,y,val=0,0,1
	for j=0,13^2 do 
	 for i=0,sqrt(val-1) do
	  local layer=((sqrt(val*4))%4)\1/4  
	  pset(x,y,✽(layer,val)) 
	  x+=cos(layer)
	  y+=sin(layer)
	  val+=1 
	 end
	 if(j%5==0)flip()
	end
end

cls()
flip()
camera(-64,-64)
rect(-46,-44,44,44)

spiral(function(l,v) return l*4 end)
spiral(function(l,v)return sqrt(l+v)end)
spiral(function(l,v)return ((l+.2)&v/10)*10end)
spiral(function(l,v)return v%5 end)
spiral(function(l,v)return tonum(prim(v))*13 end)
extcmd"video"